Skin of the back and scapular region : Sensory nerve supply of

skin :post. Rami of spinal N. 1-skin of the neck : by post. Rami of cervical Ns. C2-C7 except C1 and C8 spinal Ns. 2-skin of back of chest : by post.rami of upper 6 thoracic Ns. 3-skin of back of (loin) abdomen : by lower 6 thoracic Ns. 4-skin of buttock (gluteal): by upper 3 lumbar Ns.

Blood Supply : post branches of post. Intercostal & lumbar arteries. Veins drain into azygos veins & I.V.C.

Lymph drainage : above iliac crest into post.axillary L.Ns.

Muscles of the back and scapular regionsMuscles of the back and scapular regions

Rotator CuffRotator Cuff4 muscles : supraspinatus ,infraspinatus,teres minor & subscapularis.

They assist in holding head of humerus in glenoid cavity of scapula during movements of shoulder joint, so, they assist in stabilizing shoulder joint.

The cuff lies on the anterior, posterior & superior aspects of shoulder joint.

It is deficient inferiorly,so it is the site of weakness

Quadrangular spaceQuadrangular spaceIt is an intermuscular space ,bounded above by subscapularis & capsule of shoulder j. and inferiorly by teres major, medially by long head of triceps ,laterally by surgical neck of humerus.

Axillary N. + post. Circumflex humeral vessels pass backward through this space.

Spinal root of accessory nerve :It runs downward in the post.triangle of neck on the levator scapulae.

It is accompanied by 3rd & 4th cervical nerves + transverse (superficial ) cervical artery.

It passes deep to trapezius to supply it.

It can be injured in case of stab wounds in the neck.

Suprascapular nerveSuprascapular nerveIt arises from upper trunk of brachial plexus(C5+C6) in the post. Triangle of neck.

It runs downward deep to suprascapular ligament, which bridges suprascapular notch, to reach supraspinous fossa.

It supplies supraspinatus & infraspinatus & shoulder joint.

Axillary Nerve :Axillary Nerve : It arises from post.cord of brachial plexus(C5 & C6) in the axilla.

It passes backward through quadrangular space, inferior to capsule of shoulder joint and medial to surgical neck of humerus, accompanied with post. Circumflex humeral artery.

Branches : 1-articular branch to shoulder joint. 2-anterior terminal branch :it winds around surgical neck of humerus deep to deltoid to supply it & skin over lower ½ of deltoid. 3-post.terminal branch : it gives branches to teres minor + deltoid- then turns around post.border of deltoid as upper lateral cutaneous N.of arm to supply skin over lower ½ of deltoid muscle.

Sterno-clavicular Sterno-clavicular joint :joint :

Articular surfaces : between sternal end of clavicle, manubrium sterni, and 1st costal cartilage.

Type :plane synovial joint.

Capsule : is attached to margin of articular surfaces.

Ligaments : 1-anterior & post. sternoclavicular ligaments to reinforce the capsule in front & behind joint. 2-Accessory ligament (costo-clavicular ligament) : connects inferior surface of medial(sternal) end of clavicle to the junction of 1st rib & its costal cartilage.

Articular disc : it is fibro-cartilaginous disc,which divides joint cavity into 2 cavities.

Synovial membrane : lines the capsule inside the joint.

Sterno-clavicular Sterno-clavicular joint :joint : Nerve supply : supraclavicular +

nerve to subclavius.

Movements : 1-forward & backward movement of clavicle takes place in medial compartement. 2-elevation & depression of clavicle takes place in lateral compartement

Forward movement of clavicle : by serratus anterior.

Backward movement of clavicle : by trapezius & rhomboids.

Elevation of clavicle : by trapezius, sterno-cleidomastoid, levator scapulae & rhomboids.

Depression of clavicle : by pectoralis minor & subclavius.

Acromio-clavicular joint Acromio-clavicular joint Articulation : between acromion & lateral end of clavicle.

Type :plane synovial j.

Capsule : surrounds j.and is attached to the articular surfaces.

Ligaments : 1-sup.& inf. acromio-clavicular ligaments : reinforce the capsule. 2-accessory ligament (coraco-clavicular lig.) :from coracoid process to undersurface of clavicle.

Articular disc :a wedge-shaped fibrocartilaginous disc projects into joint cavity from above.

Acromio-clavicular joint Acromio-clavicular joint Synovial membrane : lines capsule.

Nerve supply : supra-scapular N.

Movements :a gliding movement takes place when scapula rotates or when clavicle is elevated or depressed.

Relations; -anterior :deltoid -posterior : trapezius. -superiorly :skin

Muscles of Shoulder RegionMuscles of Shoulder Region

•Deltoid.

•Supraspinatus.

•Infraspinatus.

•Subscapularis.

•Teres minor.

•Teres major.

N.B : Supraspinatus, infraspinatus, teres minor and Subscapularis--- these are Rotator cuff muscles, playing an important role in keeping the head od humerus in contact with the glenoid cavity during movements of shoulder joint.

Shoulder jointShoulder jointArticulation : 1-head of humerus. 2-glenoid cavity of scapula, which is deepened by fibrocartilaginous rim called the glenoid labrum (intra-capsular).

Type : ball & socket synovial j

Capsule :it surrounds joint –medially : it is attached to margin of glenoid cavity outside the labrum.

-laterally : it is attached to anatomical neck of humerus +transverse humeral ligament.

Anterior view

Shoulder jointShoulder joint

Sagittal section

-It is thin & lax specially inferiorly, thus allowing a wide range of mobility.

-It is strengthened by ligaments & tendons of rotator cuff muscles : (supra-spinatus, infra-spinatus, teres minor & subscapularis).

Long head of biceps is intracapsular.

Long head of triceps supports the capsule during abduction of arm.

Capsule :

Shoulder jointShoulder jointopenings in the capsule:

1-an opening in anteromedial part, the synovial membrane passes through this opening to form subcapsularis bursae beneath subscapularis, and separates subscapularis from front of capsule.

2-an opening deep to transverse ligament of humerus at upper end of bicipital groove, it transmits tendon of biceps, surrounded by a synovial tube.

Anterior view

Ligaments of Shoulder jointLigaments of Shoulder jointIntra-capsular Ligaments 1-Glenohumeral ligaments : are 3 bands of fibrous tissue that strengthen the front of capsule. 2- Transverse humeral ligament : strengthens the capsule and bridges the groove between the 2 tuberosities- tendon of long head of biceps passes beneath the ligament Extrapsular ligament : 3- Coraco-humeral ligament : strengthens the capsule above and extends from root of coracoid process to greater tuberosity of humerus.

Accessory ligaments : 4-Coraco-acromial ligament : extends between coracoid process & acromion of scapula.

Shoulder jointShoulder joint

Synovial membrane : -lines the capsule interiorly. -it is attached to margins of hyaline cartilage covering the articular surfaces. -it forms a tubular sheath around tendon of long head of biceps. -it passes through opening in the capsule to form subscapularis bursa (between capsule & subscapularis).

Nerve supply : axillary N. & supra-scapular nerve(C5,6).

Interior of joint Sagittal section

Shoulder jointShoulder joint

Sagittal section

Relations :

Anteriorly : subscapularis , axillary vessels & brachial plexus.

Posteriorly : infraspinatus & teres minor .

Superiorly : Supraspinatus, subacromial bursa, coraco-acromial ligament & deltoid mus.

Inferiorly : long head of triceps, axillary N.& post. circumflex humeral ves.

Tendon of long head of biceps passes through the joint and emerges beneath the transverse lig.

Movements of shoulder jointMovements of shoulder jointFlexion :carries arm forwards & medially, it is performed by : -Anterior Fs.of deltoid. -Pectoralis major (clavicular head) -Biceps (short head) & Coracobrachialis.

Extension :carries arm backwards, it is performed by: -Posterior Fs.of deltoid. --Teres major. -Latissimus dorsi.

Abduction :movement of arm laterally & upwards, it occurs in 3 stages : -1st stage from 0-15, by supraspinatus, it initiate movement of abduction.

Movements of shoulder jointMovements of shoulder joint-2nd stage : from 15-90, occurs by middle Fs. Of deltoid. -3rd stage : more than 90, occurs by combined action of Serratus anterior & Trapezius.

Adduction : by -Pectoralis major. -Teres major. -latissimus dorsi. -helped by subscapularis & Teres minor.

Medial rotation : -Anterior Fs. Of deltoid. -pectoralis major. –Teres major –latissimus dorsi. -Subscapularis

Lateral rotation : by -Posterior Fs. Of deltoid. -Infraspinatus. -Teres minor.

Movements of shoulder jointMovements of shoulder joint

15-90

0-15

Above 90

Circumduction : is a combination of flexion, abduction, extension & adduction

Scapula & upper limb are suspended from clavicle by strong coraco-clavicular lig.

In abduction above head, greater tuberosity of humerus comes in contact with acromion of scapula.

(S)

(D)Middle fibers

(T+SA)

Arterial Anastomosis around Scapula & Arterial Anastomosis around Scapula & ShoulderShoulder

It occurs between the branches of 1st part of subclavian & 3rd part of axillary artery.

It occurs on the bone at inferior angle of scapula, in subscapular, supraspinous & infraspinous fossae.

Branches from 1st part of subclavian artery : 1-Suprascapular artery :lies above suprascapular ligament, is distributed to supraspinous & infraspinous fossae. 2-Deep branch of superficial cervical artery : It runs down on medial border of scapula into inferior angle of scapula.

Arterial anastomosis around the Arterial anastomosis around the scapula & shoulderscapula & shoulder

Branches from 3rd part of axillary artery : 1-Subscapular artery: -It descends along lower border of subscapularis (into inferior angle & subscapular fossa). -It gives circumflex scapular artery. 2-Circumflex scapular artery: it pass deep to teres minor to pass into infraspinous fossa.

Both anterior & posterior circumflex humeral arteries form anastomosing circle around surgical neck of humerus to supply shoulder joint.

The Cubital FossaThe Cubital FossaIt is a triangular depression that lies in front of ellbow.

Boundaries : -base : imaginary line between 2 epicondyles of humerus –apex : overlapping of brachioradialis to pronator teres. -laterally : brachioradialis -medially : pronator teres. –floor : supinator . & brachialis. -Roof : skin, fascia, & bicipital aponeurosis.

Contents :from medial to lateral: 1-median N. 2-bifurcation of brachial artery into ulnar & radial arteries. 3-tendon of biceps. 4-radial N. & its deep branch. 5-supratrochlear Lymph Node.

The Cubital FossaThe Cubital Fossa

Brachial artery terminates into radial & ulnar arteries at the neck of radius.

Radial artery leaves fossa by passing under-cover of brachioradialis.

Ulnar artery leaves fossa by passing deep to pronator teres.

Median nerve leaves fossa by passing between 2 heads of pronator teres.

Supratrochlear lymph nodeSupratrochlear lymph nodeIt lies in superficial fascia over upper part of fossa, above trochlea.

It recevies afferent lymph vessels from : 1-3rd ,4th & 5th fingers. 2-medial part of hand. 3-medial side of forearm.

Its efferent lymph vessels accompany basilic vein to end in lateral group of axillary L.Ns.

Cutaneous nerves of forearmCutaneous nerves of forearmLateral cutaneous nerve of forearm : -it is the continuation of musculocutaneous nerve –it gives anterior & posterior branches.

Medial cutaneous nerve of forearm : -it is a branch of medial cord of brachial plexus. -it gives anterior & posterior branches to supply medial ½ of front of forearm & medial side of forearm respectively.

Posterior cutaneous nerve of forearm : -it is a branch of radial N. -it supplies skin of back of forearm.

Superficial veinsSuperficial veins Cephalic vein : -arises from lateral side of dorsal venous arch on the back of hand. -it ascends on lateral side of forearm into the front of cubital fossa. -In the cubital fossa, it gives median cubital vein to join the basilic vein.

Basilic vein : -arises from medial side of dorsal venous arch on back of hand. -it ascends on medial side of forearm. -In front of cubital fossa, it recevies median cubital vein.

Fascial compartments of forearm & Fascial compartments of forearm & interosseous membraneinterosseous membrane

The forearm is enclosed in a sheath of deep fascia, which is attached to the periosteum of posterior border of ulna.

Fascial sheath together with I.M.+ fibrous intermuscular septa, divides forearm into anterior, lateral & posterior compartments.

Interosseous membrane (I.M) : is a thin strong membrane uniting radius & ulna between their interosseous borders, its Fs.run obliquely downward & medially. Its lower part is pierced by anterior interosseous vessels.

Oblique cord : is a fibrous cord that extends from the radius (below tuberosity) to apex of coronoid process of ulna.

T.S in Forearm to show anterioer & T.S in Forearm to show anterioer & posterior compartmentsposterior compartments

Contents of front of forearmContents of front of forearmSuperficial muscles (lateral to media) 1-pronator teres. 2-flexor carpi radialis. 3-palmaris longus. 4-flexor digitorum superficialis 5-flexor carpi ulnaris.

Deep muscles: 1-flexor digitorum profundus.medially 2-flexor pollicis longus. laterally 3-pronator Quadratus.

Median N. : supplies all Ms.except flexor carpi ulnaris & medial ½ of flexor digitorum profundus.

Ulnar N. : supplies flexor carpi ulnaris & medial ½ of flexor digitorum profundus.

Superficial branch of radial N--has no branches in forearm.

Radial & ulnar arteries.

Anterior Fascial compartment of forearm :

Deep group of muscles of ForearmDeep group of muscles of ForearmFlexor digitorum profundus…medially

Flexor pollicis longus…laterally.

Pronator quadratus.

Median Nerve in forearmMedian Nerve in forearmIt leaves cubital fossa to enter forearm between 2 heads of pronator teres.

In the forearm, it descends in the middle, between flexor digitorum superficialis , & flexor digitorum profundus.

At the wrist, it enters hand by passing deep to flexor retinaculum.

Branches in forearm : -muscular : pronator teres,+ flexor carpi radialis, +palmaris longus + flexor digitorum superficialis. -articular : elbow, sup.radio-ulnar, wrist joints. -anterior interosseous nerve : it descends in front of interosseous membrane.

Median NerveMedian NerveBranches of anterior interoseous nerve : -muscular : flexor pollicis longus _ lateral ½ of flexor digit.profundus + pronator Q. -articular : inferior radio-ulnar joint + wrist joint. -palmar cutaneous nerve : arises above wrist j., to pierce deep fascia to descend superficial to flexor retinaculum to supply skin of lateral 2/3 of palm.

Cutaneous nerves of palm & Cutaneous nerves of palm & fingersfingers

(supplies base of thenar eminence)

Ulnar NerveUlnar Nerve At the elbow : it passes behind medial epicondyle to enter forearm by passing between 2 heads of flexor carpi ulnaris.

In the forearm, it descends in the medial side, medial to ulnar artery, deep to flexor carpi ulnaris, superficial to flexor digit.profundus.

Above wrist, it pierces deep fascia to descend superficial to flexor retinaculum and lateral to pisiform bone, between tendon of F.C.U.& F.D.S.

Branches : -muscular : flexor carpi ulnaris + medial ½ of F.D.P. -articular : to elbow joint. -palmar cutaneous : pierces deep fascia to supply skin over hypothenar eminence + skin of medial 1/3 of palm. -posterior cutaneous branch : passes posteriorly to supply skin of back of medial 1/3 of hand + skin of back of proximal phalanx of medial 1 ½ fingers, ( by 2 dorsal digital nerves).

Radial NerveRadial NerveIt pierces lateral intermuscular septum of lower arm to pass into cubital fossa.

It then passes in front of lateral epicondyle , between brachialis(medially) and / brachioradialis & ext.carpi radialis longus. At level of lateral epicondyle, it divides into superfical & deep branches.

Branches : -muscular : lateral part of brachialis + brachioradialis + ext.C.R.longus. -articular : elbow joint. -deep branch of radial N. (posterior interoseous N.) : arises from radial N. in cubital fossa in front of lateral epicondyle. It pierces supinator muscle to wind around neck of radius and reach posterior compartment of forearm between superficial & deep muscles to supply the extensor muscles. -Superficial branch :it is direct continuation of radial N., descending deep to brachioradialis. Above wrist, it pierces deep fascia and turns backwards to supply skin of lateral 2/3 of back of hand + skin of back of proximal phalanges of lateral 3 1/2 fingers.

Ulnar arteryUlnar arteryIt begins in cubital fossa at level of neck of radius as the largest terminal branch of brachial artery.

In upper part, it lies deep to flexors of forearm.

Below it becomes superficial , lies between tendons of F.C.U. & F.D.S. to pass in front of flexor retinaculum, lateral to pisiform bone (site for ulnar pulse)

Branches : -muscular. -Recurrent branches: anterior & posterior ulnar recurrent to take part in anastomosis around elbow. -Common interosseous : divides into anterior & posterior , lying in front & behind interosseous membrane and provide nutrient arteries to radius & ulna.

Branches of ulnar artery in forearm :

Muscular.

Recurrent branches that take part in anastomosis around elbow.

Branches that take part in anastomosis around wrist.

Common interosseous artery : arises from upper part of ulnar artery and after a short course divides into anterior & posterior interosseous arteries in front & behind I.M., they are nutrient to radius & ulna.

Radial arteryRadial arteryIt is the smaller terminal branch of brachial artery , begins in cubital fossa, at level of neck of radius.

It passes laterally, in front of forearm deep to brachioradialis.

Its distal part is superficial, covered by skin, superficial fascia & deep fascia. (site of radial pulse on lateral end of radius close to lateral side of tendon of flexor carpi radialis).

At wrist, it turns backwards to posterior surface of hand.

Branches : -muscular -Radial recurrent artery : takes part in anastomosis around elbow. -Superficial palmar branch : arises just above wrist, enters palm of hand to join ulnar artery to form superficial palmar arch.

Flexor Retinaculum Flexor Retinaculum (Anterior carpal tunnel)(Anterior carpal tunnel)

Cross section of the hand

it is a thickening of deep fascia that holds long flexor tendons in position in front of the wrist.

The bones of hand & flexor retinaculum form osteofascial tunnel, (carpal tunnel),for passage of median N. & flexor tendons of thumb & fingers.

Median N. lies in restricted space between tendons of F.D.S & F.C.R.

It is attached medially to pisiform bone & hook of hamate, and laterally to tubercle of scaphoid & trapezium (in which the attachment consists of superficial & deep parts to form a tunnel for passage of flexor carpi radialis tendon).

Flexor Retinaculum Flexor Retinaculum (Anterior carpal tunnel)(Anterior carpal tunnel)

Cross section of the hand

Structures passing superficial to flexor retinaculum, from medial to lateral : 1-tendon of flexor C.U. 2-ulnar N. 3-ulnar artery. 4-palmar cutaneous branch of ulnar N. 5-tendon of palmaris longus. 6-palmar cutaneous branch of median N.

Structures passing deep to flexor retinaculum from medial to lateral : 1-tendons of F.D.S + F.D.P in a common synovial sheath. 2-median N. + anterior interosseous branch. 3-anterior interosseous artery. 4-tendon of flexor pollicis longus. 5-tendon of flexor carpi radialis.

Muscles of Anterior Compartment Muscles of Anterior Compartment of Forearmof Forearm

2/3 of

¾ of

+ interosseous membrane.

Flexor carpi radialisPronator Teres +

Pronator Quadratus.

Impression on middle of lateral surface of shaft of radius

(( )

Plmaris Longus Flexor Carpi Ulnaris

Olecranon process of ulna+ upper 2/3 post.border of ulna

Their tendons pass superficial to flexor retinaculum

( )

Flexor Digitorum Superficialis

(By 4 tendons into sides of middle phalanges of medial 4 fingers.)

by 4 tendons into medial 4 fingers, each tendon divides into 2 slips on palmar surface of proximal phalanx to surround tendon of flexor digitorum profundus.

The 2 slips are inserted into sides of middle phalanx of medial 4 fingers.

Insertion :

( )

( )

Flexor Pollicis Longus Flexor Digitorum ProfundusFlexion of interphalangeal & metacarpo-phalangeal joints of thumb.

Flexion of interphalangeal & metacarpo-phalangeal joints of medial 4 fingers.

Base of

From upper 2/3 of anterior surface of radius+ I.M.

Into base of

upper ¾ of antero-medial surface of ulna + I.M.

Sensory nervesSensory nerves of of dorsum of handdorsum of handSuperficial branch of radial N. : skin of lateral 2/3 of back of hand.

Dorsal cutaneous branch of ulnar N.: skin of medial 1/3 of back of hand

Skin of back of fingers by : 1-dorsal digital branches of radial N.: skin of back of proximal phalanges of lateral 3 ½ fingers. 2-palmar digital branches of median nerve : skin of back of middle & distal phalanges of lateral 3 ½ fingers. 3-dorsal digital branches of ulnar N.: skin of back of proximal phalanges of medial 1 ½ fingers. 4-palmar digital branches of ulnar N.: skin of back of middle & distal phalanges of medial 1 ½ fingers.

Contents of Lateral fascial Contents of Lateral fascial compartment of forearmcompartment of forearm

Blood supply : radial & brachial arteries.

Nerve supply : radial N.

Upper 2/3 of

Lower 1/3 of

It helps in initiation of pronation & supination

Extensor carpi radialis longus.

Styloid process of radius

Brachioradialis

(Upper 2/3 )

Lower 1/3 of

Dorsum of base of

Posterior fascial compartment of Posterior fascial compartment of forearmforearm

Superficial Group of Muscles :

1-extensor carpi radialis brevis. 2-extensor digitorum. 3-extensor digiti minimi. 4-extensor carpi ulnaris. 5-anconeus.

Deep Group of Muscles 1-supinator. 2-abductor pollicis longus. 3-extensor pollicis brevis. 4-extensor pollicis longus. 5-extensor indicis.

Blood supply : posterior & anterior interosseous arteries of ulnar artery.

Nerve supply : deep branch of radial N.(post.interosseous N.).

Muscles of Posterior fascial Muscles of Posterior fascial Compartment of Forearm Compartment of Forearm

(Superficial muscles)(Superficial muscles)

(N.to Anconeous)

Post. Interosseous N.

Muscles of Posterior fascial Muscles of Posterior fascial Compartment of Forearm Compartment of Forearm

(Deep muscles)(Deep muscles)Post.interosseous N.

(Common ext. origin)

+ supinator crest & fossa of ulna

V-shaped area,Upper 1/3 of front,lateral & back of radius

Extensor RetinaculumExtensor Retinaculum

Cross section of the hand

it is a thickening of deep fascia that stretches across back of wrist and holds long extensor tendons in position.

It converts grooves of posterior surface of distal ends of radius & ulna into 6 separate tunnels or compartments for passage of long extensor tendons, the tunnels are separated by fibrous septa.

It is attached medially to pisiform bone & hook of hamate, and laterally to distal end of radius.

Extensor RetinaculumExtensor Retinaculum

Cross section of the hand

Structures passing superficial to extensor retinaculum from medial to lateral : 1-dorsal(posterior) cutaneous branch of ulnar N. 2-basilic vein. 3-cephalic vein. 4-superficial branch of radial N.

Posterior carpal tunnel= Structures passing deep to extensor retinaculim in each compartments (from lateral to medial) :Tendons of 1- abductor P.L +extensor P.B + radial artery. 2-extensor C.R.L +extensor C.R.B. 3-extensor pollicis longus. 4-extensor digit.+ extensor indicis 5-extensor digiti minimi. 6-extensor carpi ulnaris.

Structures passing Structures passing deep todeep to extensor extensor retinaculum retinaculum (posterior carpal tunnel)(posterior carpal tunnel)

(from lateral to medial)(from lateral to medial)

Structures passing Structures passing deep todeep to extensor extensor retinaculum retinaculum (posterior carpal tunnel)(posterior carpal tunnel)

Insertion of long extensor tendonsInsertion of long extensor tendons

Extensor digitorum muscle gives rise to 4 tendons for medial 4 fingers.

Tendon to index finger is joined on its medial side by tendon of extensor indicis, and tendon to little finger is joined on its medial side by 2 tendons of extensor digiti minimi.

On back of each finger, the extensor tendon expands to join the fascial expansion called extensor expansion.

Each extensor expansion divides into : a central part, inserted into base of middle phalanx, and 2 collateral parts to insert into base of distal phalanx.

Dorsal extensor expansionDorsal extensor expansion

Each dorsal extensor expansion receives the insertion of : 1-an interosseous muscle on the medial side. 2-an interosseous & lumbrical muscles on the lateral side.

Radial arteryRadial artery in in dorsum of handdorsum of handIt reaches back of hand by passing between lateral collateral ligament of wrist joint and tendons of abductor pollicis longus + extensor pollicis brevis.

It passes beneath tendon of extensor P.L to reach the interval between 2 heads of 1st dorsal interosseous to enter palm of hand.

On reaching palm, it curves medially between oblique & transverse heads of adductor pollicis to join deep branch of ulnar artery to form “deep palmar arch”.

Anatomic snuffbox : it is a skin depression on lateral side of wrist, bounded medially by tendon of extensor pollicis longus and laterally by tendons of abductor pollicis longus & extensor pollicis brevis.

Branches of radial artery on the dorsum Branches of radial artery on the dorsum of handof hand

Dorsal digital artery to lateral side of dorsum of the thumb.

1st dorsal metacarpal artery ,which divides into 2 dorsal digital branches for adjacent sides of thumb & index finger.

Anatomic SnuffboxAnatomic Snuffbox

it is a skin depression on lateral side of wrist, bounded medially by tendon of extensor pollicis longus and laterally by tendons of abductor pollicis longus & extensor pollicis brevis.

Clinically ,it is the site for radial artery pulsations.

Dorsal venous archDorsal venous arch

It lies in superficial fascia (subcutaneous tissue) ,proximal to metacaro-phalangeal joints ,and drains on lateral side into cephalic V. and on medial side into basilic V.

Venous blood from hand drains into the arch via dorsal digital veins.

Radial Nerve in lateral & posterior compartmentRadial Nerve in lateral & posterior compartmentIt pierces lateral intermuscular septum of lower arm to pass into cubital fossa.

It then passes in front of lateral epicondyle , between brachialis(medially) and / brachioradialis & ext.carpi radialis longus (laterally). At level of lateral epicondyle, it divides into superfical & deep branches.

Branches : -muscular : lateral part of brachialis + brachioradialis + ext.C.R.longus. -articular : elbow joint.

--Superficial branch :it is direct continuation of radial N., descending deep to brachioradialis. Above wrist, it pierces deep fascia and turns backwards to supply skin of lateral 2/3 of back of hand + skin of back of proximal phalanges of lateral 3 1/2 fingers. -Deep branch (posterior interosseous N.) : Arises from radial N. in cubital fossa in front of lateral epicondyle. It pierces supinator muscle to reach posterior compartment of forearm, between superficial & deep muscles to supply the extensors and ends in wrist joint. (so, it gives muscular & articular branches).

Anterior & posterior interosseous arteriesAnterior & posterior interosseous arteries (arteries of posterior compartment of forearm)(arteries of posterior compartment of forearm)

They arise from common interosseous artery, a short branch of ulnar artery in upper part of front of forearm,which divides into 2 branches :

Anterior interosseous artery : descends in front of I.M. Above wrist , it pierces I.M.to reach back descending behind I.M. and takes part in anastomosis around wrist.

Posterior interosseous artery: a small branch which passes above I.M. to reach back of forearm. It ends by anastomosing anterior interosseous artery and takes part in anastomosis around wrist.

The 2 arteries supply radius & ulna + muscles lying in front & behind I.M.

Anterior & posterior interosseous arteriesAnterior & posterior interosseous arteries

Anterior interosseous arteryAnterior interosseous artery

Radial arteryRadial artery in the lateral side of forearm , in the lateral side of forearm , where it deviates posteriorly to reach where it deviates posteriorly to reach

anatomical snuffboxanatomical snuffbox on the on the dorsum of handdorsum of hand

Lower 1/3 of

Extensor carpi radialis brevis & extensor carpi ulnaris.

Front ofFront of

Dorsum of Base of

Dorsum of base of

Common ext. origin + post. Border of ulna

Extensor Digitorum & Extensor Digiti minimi

Insertion of ext.digitorum : by 4 tendons into medial 4 fingers.

Each tendon expand to form ext.expansion, which divides into central part & 2 collateral parts.

Central part is inserted into post.surface of base of middle phalanx.

2 collateral parts are inserted into post.surface of base of distal phalanx.

for1-

2-

Into its extensor expansion

Anconeous

Post.surface of shaft of radius

Post.surface of shaft of ulna

Olecranon process of ulna(lateral surface).

Abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis .

Middle of Post.surface of shaft of radius +ulna + I.M.

Middle 1/3 of Post.surface of shaft of ulna +I.M.

Middle 1/3 of post.surface of radius +I.M.

Lower 1/3 of post.surface of ulna + I.M.

Into extensor expansion of index finger

Supinator muscle.

Lateral epicondyle of humerus.+ supinator crest& fossa of ulna

Into V-shaped area in Neck & upper 1/3 of shaft of radius

Cutaneous nerves of palmCutaneous nerves of palmPalmar cutaneous branch of median N. : supplies skin of lateral 2/3 of palm.

Palmar cutaneous branch of ulnar N. : supplies skin of medial 1/3 of palm.

Lateral cutaneous N. of forearm or/superficial branch of radial N. : supplies skin over base of thenar eminence.

Skin of Palmar surfaces of fingers is supplied by : 1-palmar digital branches of median N…. For palmar surfaces of lateral 3 ½ fingers. 2-palmar digital branches of ulnar N…for palmar surfaces of medial 1 ½ fingers.

Palmar aponeurosisPalmar aponeurosisIt is a triangular thickening of deep fascia, occuping central part of the palm.

Its apex is directed upwards and is attached to flexor retinaculum and gives insertion to palmaris longus muscle.

Its base is directed downwards and is divided into 4 slips for medial 4 fingers.

Each slip divides into 2 bands which diverge from each other and pass backwards and finally fuse with the fibrous flexor sheath and deep transverse metacarpal ligaments.

Its medial & lateral borders send fibrous septa into palm to form palmar fascial spaces.

Its function to protect tendons,nerves & blood vessels in the palm.

Palmaris brevis musclePalmaris brevis muscle

It is a thin muscle which is present in superficial fascia of palm, in front of hypothenar eminence.

Origin : flexor retinaculum & palmar aponeurosis.

Insertion : skin of medial side of palm.

Nerve supply : superficial terminal branch of ulnar N.

Function : it deepens cup of hand and enables hand to hold a rounded objects.

Structures passing superficial to Structures passing superficial to flexor retinaculumflexor retinaculum

The carpal TunnelThe carpal Tunnel

The long tendons of fingers & thumb and median N. pass through the tunnel. The tendons of F.D.P. lie behind superficialis tendons, together in a common synovial sheath.

Tendon of F.P.L.muscle runs through lateral part of tunnel in its own synovial sheath.

Median N. passes beneath flexor retinaculum in a restricted space between F.D.S & F.C.R muscles.

Carpal tunnel syndromeCarpal tunnel syndrome

It is a burning pain or ‘pins & needles’ along the It is a burning pain or ‘pins & needles’ along the distribution of distribution of median nervemedian nerve to lateral 3 ½ to lateral 3 ½ fingers + weakness of thenar muscles (abductor fingers + weakness of thenar muscles (abductor P.brevis, flexor P. brevis + opponens pollicis).P.brevis, flexor P. brevis + opponens pollicis).It is due to It is due to compression of median N.compression of median N. within within the tunnel as a result of thickening of synovial the tunnel as a result of thickening of synovial sheaths of flexor tendons or arthritis of carpal sheaths of flexor tendons or arthritis of carpal bones.bones.It needs surgical decompression of tunnel.It needs surgical decompression of tunnel.No paresthesia over thenar eminenceNo paresthesia over thenar eminence due to due to palmar cutaneous branch of median N.palmar cutaneous branch of median N. passes passes superficial to flexor retinaculum.superficial to flexor retinaculum.

Fibrous flexor sheathsFibrous flexor sheaths

It extends from head of metacarpal bone to base of distal phalanx.

Its proximal end is open and is contineous with palmar aponeurosis.

Its distal end is closed and is attached to palmar surface of distal phalanx.

Its function to hold flexor tendons (F.D.S + F.D.P, & F.pollicis longus) and their synovial sheaths.

Flexor synovial sheathsFlexor synovial sheathsSynovial sheath of tendon of flexor pollicis longus (radial bursa) : -begins above flexor retinaculum and extends to the insertion of tendon (distal phalanx).

Common flexor synovial sheath : -surrounds the 8 tendons of F.D.S & F.D.P (ulnar bursa) -begins above the flexor retinaculum -ends in the middle of palm. -continuous with the synovial sheath of little finger. -the sheaths of index,middle & ring fingers do not communicate with the common sheath, they have digital synovial sheaths, that ends at distal phalanges.

Vincula tendinumVincula tendinum

They are long threads (vincula longa) or short triangular bands (vincula brevia).

They are vascular folds of synovial membrane that connect the tendons to palmar surface of phalanges.

Their function : 1-allow the long tendons to move smoothly beneath flexor retinaculum and fibrous flexor sheaths. 2-carry blood supply to tendons

4 Lumbrical muscles4 Lumbrical muscles

Origin : lateral sides of tendons of F.D.P.

Insertion : pass backwards along lateral sides of metacarpo-phalangeal joints of medial 4 fingers into lateral sides of extensor expansions of these fingers.

N.supply : lateral 2 lumbricals (1st &2nd )by median N. – medial 2 lumbricals(3rd &4th ) by deep branch of ulnar N.

Action : with interossei, they flex metacarpo-phalangeal joints and extend interphalangeal joints of medial 4 fingers (Writing position).

Interossei musclesInterossei muscles

Anterior view

4 Palmar interossei & 4 dorsal interossei.

Origin : metacarpal bones.

Insertion :proximal phalanges & dorsal extensor expansion.

N.supply : deep branch of ulnar N.

Action : -palmar interossei : adduction of fingers to the middle line of middle finger. -dorsal interossei : abduction of fingers from middle line of middle finger. -both lumbricals + interossei …..’’writing position’’

Origin & insertion & action of Origin & insertion & action of palmar & dorsal interossei musclespalmar & dorsal interossei muscles

Short muscles of thumb Short muscles of thumb (thenar eminence muscles) (thenar eminence muscles)

Abductor pollicis brevis, laterally.

Flexor pollicis brevis, medially.

Opponens pollicis, deep.

Adductor pollicis (obliqe & transvere heads).

N.supply : all are supplied by median N. EXCEPT adductor pollicis by deep branch of ulnar N.

Abduction & adduction = carpo-metacarpal joint.

Flexion = metacarpo-phalngeal joint.

Short muscles of little finger Short muscles of little finger (hypothenar eminence muscles)(hypothenar eminence muscles)

Abductor digiti minimi.

Flexor digiti minimi.

Opponens digiti minimi.

N.supply :all these muscles are supplied by deep branch of ulnar N.

Anterior view

Ulnar artery in the palmUlnar artery in the palm

Anterior view

It enters hand by passing superficial to flexor retinaculum, lateral to ulnar N. and pisiform bone.

In the hand it divides into deep & superficial palmar branch. -superficial palmar branch : is a direct continuation of ulnar artery. It joins superficial palmar branch of radial to form superficial palmar arch,.in front of long flexor tendons and behind palmar aponeurosis. The curve of arch lies at level with the distal border of fully extended thumb. It gives 4 palmar digital arteries to the fingers. -deep branch of ulnar artery : passes backwards (accomppanied by deep branch of ulnar N.) between abductor digiti minimi & flexor digiti minimi to join radial artery to form deep palmar arch.

Branches of Superficial palmar archBranches of Superficial palmar arch

Palmar digital artery …to medial side of little finger.

3 common palmar digital arteries : each one divides into 2 palmar digital branches to adjacent sides of fingers. They are joined with : common palmar metacarpal arteries of deep palmar arch.

Radial artery in the palmRadial artery in the palm

It leaves forearm by winding around lateral aspect of wrist into dorsum of hand.

It leaves dorsum of hand by turning forward between the 2 heads of 1st dorsal interosseous muscle.

It enters palm curving medially between the oblique & transverse heads of adductor pollicis to join deep branch of ulnar artery to form deep palmar arch, which lies beneatn long flexor tendons and in front of metacarpal bones & interosseous muscles. The curve of arch lies at a level with proximal border of extended thumb.

Branches of Branches of radial arteryradial artery in the palm : in the palm :

Arteria radialis indicis : supplies lateral side of index finger.

Arteria princeps pollicis : divides into two to supply lateral & medial sides of thumb.

Branches of deep palmar arch:

3 common palmar metacarpal arteries : they run in 2nd ,3rd &4th inter-metacarpal spaces to end by joining common palmar digital arteries at roots of fingers.

Median nerve of the palmMedian nerve of the palmCourse : -it leaves forearm to enter hand by passing deep to flexor retinaculum. –it ends in the palm by dividing into terminal lateral & medial branches.

Branches in the hand : -the 2 terminal branches give rise to : 1-muscular branches : to supply 5 Ms. (Abductor pollicis brevis, flexor pollicis brevis, Opponens pollicis) + lateral 2 lumbricals (1st & 2nd ). 2-cutaneous branches : by 5 palmar digital branches to supply skin of palmar surface of lateral 3 ½ of fingers. They also supply nail beds & skin over back of middle and distal phalanges of same fingers.

palmar cutaneous branch of median nerve : in the forearm and crosses superficial to flexor retinaculum to supply skin of lateral 2/3 of palm.

Ulnar nerve in the palmUlnar nerve in the palm Course : -it enters hand by passing superficial to flexor retinaculum, it divides into terminal superficial & deep branch. -superficial branch : -passes deep to palmaris brevis to supply it. -it gives 2 palmar digital branches for medial 1 ½ fingers. -deep branch : -passes backwards between abductor D.M. & flexor D.M. and then turns laterally across palm deep to flexor tendons proximal to deep palmar arch. -supplies 14 Ms. (3 hypothenar + medial 2 lumbricals 3rd ,4th + 4 palmar interosseoi + 4 dorsal interosseoi + adductor pollicis).

palmar cutaneous branch of ulnar nerve : -arises in forearm above wrist, passing superficial to flexor retinaculum to supply skin of medial 1/3 of palm of hand.

Pulp space of fingersPulp space of fingers

Deep fascia of pulp of each finger fuses with periosteum of terminal phalanx.

Each pulp space is filled with fat and is subdivided by fibrous septa .

Terminal branch of digital artery that supplies diaphysis of terminal phalanx, runs through this pulp space, while the blood supply of epiphysis is proximal to pulp space.

Felon (pulp –space infection) : common case leads to infection of terminal phalanx and necrosis of diaphysis, but epiphysis is saved.

Palmar fascial spacesPalmar fascial spacesFrom medial border of palmar aponeurosis, a fibrous septum passes backward and attached to 5th metacarpal bone. Medial to this septum is a medial fascial compartment containing 3 hypothenar muscles + loose C.T.

From the lateral border of palmar aponeurosis, a second fibrous septum passes obliquely backward to 3rd metacarpal bone. It divides palm into thenar space (contains 1st lumbrical) & midpalmar space (contains 2nd ,3rd ,4th lumbricals).

3rd fibrous septum passes backward from lateral side to attach to 1st metacarpal, lateral to this septum a lateral fascial compartment containing muscles of thenar eminence.